Paving composition



Patented Dec. 16, 1924.

PATENT OFFICE.

CHARLES SWAN, OF SAN FRANCISCQ-CALIFORNIA.

PAVING- COMPOSITION.

No Drawingl To all whom it may concern:

Be it known that I, CHARLES SWAN, a citizen of. the United States,residing at San Francisco, in the county of San Francisco and State ofCalifornia, have invented certain new and useful Improvement in PavingCompositions, of Which the following is a full, clear, and exactdescription.

My invention relates to concrete compositions for pavements andsidewalks which contain as a binder solid bituminous products, such asasphalt and mineral pitch, and an object of my invention is to increasethe toughness, elasticity and durability of such compositions.

The subject matter ofthisapplication is the same as that of my former,abandoned application, Serial #247A7 9, filed July 31, 1918. I

The improved qualities of my pavement are due essentially to the use ofdiatomaceous earth in the composition. 1 have discovered thatdiatomaceous earth, when added in a proper proportion to thecomposition, not only causes the pavement'to be unafiected bytemperature changes, but also is cementitious in its effect andamalgamates the concrete, and toughens the avement and renders it moreelastic an durable. The diatomaceous earth may be mixed into the asphaltor bitumen mixture while the latter is hot, or it may be mixed into themineral filler, or it may be divided between the binder and fillerbefore the two are mixed.

According to conditions, I have found that. when mixed into thebinder,-the pro portion of diatomaceous earth can vary fromapproximately 10% to approximately 35%. For most uses in pavingmaterials, the binder or bitumen mixture may contain approximately from55% to 85% of asphalt, from 5% to 10% of crude petroleum oil and from10%-to 35% of diatomaceous earth. Usually about of diato: maceous earthis sufiicient. The filler or base of the paving composition mayconsist,.as is usual, of crushed stone and sand. A suitable avement maybe made of a filler consisting of crushed stone of a size the pavementis laid ping is formed of Application filed August 8, 1924. Serial No.730,907.

from approximately three inches square and all the smaller stone down tothe dust of the stone which results from the crushing and which is mixedin the concrete.

As an example of a durable pavement, 5 fine sand up to meshes to thesquare inch and coarse sand to one-quarter of an inch square is mixed inwith the crushedrock, and this mixture is put in a vessel where it isagitated and subjected to heat. When 60 this base material or filler isdried and heated so that all the moisture has escaped, the binder orbitumen mixture, composed of asphalt, crude petroleum oil,anddiatomaceous earth in proper proportions is passed into the vesselWith the base material. This mixture is agitated sufiiciently tothoroughly mix into a bituminous concrete, after which it is transportedto the place where and uniformly raked-7 out and then rolled and stampedsufficiently to make the pavement compact.

The concrete pavement is laid on a dry, solid base to any desiredthickness. When a pavement of less than three inches is laid,

the size of the crushed stone will be regulated accordingly. The top orsurface capa sprinkling of the bitumen mixture of asphalt, crudepetroleum oil and diatomaceous earth, which may be 'mixed in the usualway with sand, to make the pavement water-proof and preventslipperiness. I have also found that coarse horse hair or other kind ofhair is an excellent substitute for or addition to the sand for thispurpose. In case of a sidewalk, fine and coarse sand is mixed with thebitumen binder composed of asphalt or any bituminous material, crudepetroleum oil and diatomaceous earth, and the mixture is rolled orotherwise properly compacted.

I claim:

1. A binder mixture for pavements and the like consisting of a solidbituminous product, diatomaceous earth and petroleum oil.

2. A paving composition consisting ofa solid bituminous product, crudepetroleum, diatomaceous earth, sand and crushed stone.

3. As a'paving composition, the combination of a binder of solidbitumen, diatomaceous earth and crude petroleum, and a filler ofpulverized rook, I

4. Aswe, paving composition the combination maceous earth and ci'udepetroleum, and a filler of crushed rock ands'and.

5. As a paving composition the combinaof a binder of solid bitumen,diato tion of a binder of solid bitumen, diatomaceous earthv and crudepetroleum, and a In Witness whereof, I hereunto subscribe my signature.

CHARLES SWAN.

varying size including the stone 1

